TABLES 113-114. 



133 



RELATIVE DENSITY OF MOIST AIR FOR DIFFERENT PRESSURES 



AND HUMIDITIES. 



TABLE 113. Values of ^, from h = 1 to h = 9, for the Computation of Different Valuei 

 of the Ratio of Actual to Normal Barometric Pressure. 



This gives the density of moist air at pressure h in terms of the same air at normal atmosphere pres- 

 sure. When air contains moisture, as is usually the case with the atmosphere, we have the 

 following equation for pressure term: h=B 0.378^, where e is the vapor pressure, and B the 

 corrected barometric pressure. When the necessary psychrometric observations are made the value 

 of e may be taken from Tabl* 189 and then 0.3782 from Table 115, or the dew-point may be found 

 and the value of 0.378* taken from Table 115. 



EXAMPLES OF USE OF THE TABLE. 



To find the value of when h = 754.3 

 760 



h =: 700 gives .92105 

 50 ' .065789 

 4 .005263 



vJ .000395 



754-3 -992497 



To find the value of when h 5.73 

 760 



k = 5 gives .0065789 

 .7 ' ; .0009210 

 .03 " .0000395 



5-73 



.0075394 



TABLE 114. Values of the logarithms of * Q for values of h between 80 and 340. 



Values from 8 to 80 may be got by subtracting i from the characteristic, and from 0.8 to 8 by subtracting 2 from the 



characteristic, and so on. 



SMITHSONIAN TABLES. 



